Buffered versus unbuffered local anesthesia for inferior alveolar nerve block injections in children: a systematic review
Local anesthetics used in dentistry are acidic. The solution sent from the manufacturer uses hydrochloride salts to improve solubility, stability, and shelf life. These hydrochloride salts cause the pH to be between 3.5-5, upon injecting the anesthetic, if left in this acidic state, disrupts the local tissue pH for a prolonged period. A recent systematic review published in August 2020 in the Journal of Dental Anesthesia and Pain Medicine aimed to evaluate and compare the efficacy and level of pain of buffered and unbuffered local anesthesia in children.1
Five studies published between 2013 and 2019 were included in the review. All five studies were randomized, three were double-blinded. Attrition bias was reported in one study, while selective reporting bias was not observed in any of the studies. The anesthetic in all studies was diluted with sodium bicarbonate, the dilution ratio in 3 studies was 10:1 and 9:1 in one study. The last study did not report the dilution ratio. The pH of unbuffered local anesthesia in the studies ranged between 3.85 to 4.33, the buffered local anesthesia pH level ranged between 7.22 and 7.32.
Four of the studies evaluated child-reported pain perception of buffered and unbuffered local anesthetic. One study reported significantly lower pain scores with the buffered local anesthetic, while three studies reported no significant difference. One study did not measure these parameters; therefore, it was excluded from this portion of the review. Three studies also reported on observer-reported pain reaction in children, all three reported no significant difference.
The secondary outcome reviewed was “onset time of anesthesia.” Four of the five studies reported on this outcome. Two of the four studies reported a “significantly lower onset time of anesthesia for buffered solutions.” The other two reported no significant difference.
The authors concluded, “Buffering LA solution may reduce discomfort due to IANB injection and lower the initial onset time of anesthesia after IANB administration in children. More randomized controlled trials with adequate sample sizes should be carried out to validate the accuracy of these results.”
Does your office buffer local anesthesia? Have you noticed or your patients reported more comfort with buffered anesthesia? If further studies confirm the findings will you consider implementing buffering of local anesthesia for better comfort for your patients?
- Tirupathi SP, Rajasekhar S. Buffered versus unbuffered local anesthesia for inferior alveolar nerve block injections in children: a systematic review. J Dent Anesth Pain Med. 2020 Oct;20(5):271-279. doi: 10.17245/jdapm.2020.20.5.271. Epub 2020 Oct 30. PMID: 33195805; PMCID: PMC7644362.